Re: mlx5: CX7: fw_tracer: crash at mlx5_tracer_print_trace()

[Usama Arif <usamaarif642@gmail.com>]

On 15/10/2025 12:13, Moshe Shemesh wrote:
> 
> 
> On 10/9/2025 3:42 PM, Breno Leitao wrote:
>> Hello,
>>
>> I am seeing a crash in some production host in function
>> mlx5_tracer_print_trace() that sprintf a string (%s) pointing to value
>> that doesn't seem to be addressable. I am seeing this on 6.13, but,
>> looking at the upstream code, the function is the same.
>>
>> Unfortunately I am not able to reproduce this on upstream kernel easily.
>> Host is running ConnectX-7.
>>
>> Here is the quick stack of the problem:
>>
>>     Unable to handle kernel paging request at virtual address 00000000213afe58
>>
>>     #0  string_nocheck(buf=0xffff8002a11af909[vmap stack: 1315725 (kworker/u576:1) +0xf909], end=0xffff8002a11afae0[vmap stack: 1315725 (kworker/u576:1) +0xfae0], s=0x213afe59, len=0) (lib/vsprintf.c:646:12)
>>     #1  string(end=0xffff8002a11afae0[vmap stack: 1315725 (kworker/u576:1) +0xfae0], s=0x213afe58) (lib/vsprintf.c:728:9)
>>     #2  vsnprintf(buf=0xffff8002a11af8e0[vmap stack: 1315725 (kworker/u576:1) +0xf8e0], fmt=0xffff10006cd4950a, end=0xffff8002a11afae0[vmap stack: 1315725 (kworker/u576:1) +0xfae0], str=0xffff8002a11af909[vmap stack: 1315725 (kworker/u576:1) +0xf909], old_fmt=0xffff10006cd49508) (lib/vsprintf.c:2848:10)
>>     #3  snprintf (lib/vsprintf.c:2983:6)
>>
>> Looking further, I found this code:
>>
>>          snprintf(tmp, sizeof(tmp), str_frmt->string,
>>                   str_frmt->params[0],
>>                   str_frmt->params[1],
>>                   str_frmt->params[2],
>>                   str_frmt->params[3],
>>                   str_frmt->params[4],
>>                   str_frmt->params[5],
>>                   str_frmt->params[6]);
>>
>>
>> and the str_frmt has the following content:
>>
>>     *(struct tracer_string_format *)0xffff100026547260 = {
>>     .string = (char *)0xffff10006cd494df = "PCA 9655E init, failed to verify command %s, failed %d",
>>     .params = (int [7]){ 557514328, 3 },
>>     .num_of_params = (int)2,
>>     .last_param_num = (int)2,
>>     .event_id = (u8)3,
>>     .tmsn = (u32)5201,
>>     .hlist = (struct hlist_node){
>>         .next = (struct hlist_node *)0xffff0009f63ce078,
>>         .pprev = (struct hlist_node **)0xffff0004123ec8d8,
>>     },
>>     .list = (struct list_head){
>>         .next = (struct list_head *)0xdead000000000100,
>>         .prev = (struct list_head *)0xdead000000000122,
>>     },
>>     .timestamp = (u32)22,
>>     .lost = (bool)0,
>>     }
>>
>>
>> My understanding that we are printf %s with params[0], which is 557514328 (aka
>> 0x213afe58). So, sprintf is trying to access the content of 0x213afe58, which
>> is invalid, and crash.
>>
>> Is this a known issue?
>>
> 
> Not a known issue, not expected, thanks for reporting.
> We will send patch to protect from such crash.
> Please send FW version it was detected on.

Hello!

I work with Breno and just following up on his behalf while he is away. Just wanted to check
if there was an update on the patch?

Thanks
Usama
> 
> Thanks,
> Moshe.
> 
>> Thanks
>> --breno
>>
>